1. Field of Invention
The present invention pertains to the field of imaging systems. More particularly, this invention relates to controlling an imaging array not having black cells using an array controller that is adapted to imaging arrays having black cells.
2. Art Background
A variety of imaging systems commonly include an array of photo-sensitive semiconductor cells for obtaining samples of an image. Each cell of such an imaging array usually generates an electrical signal in response to incident light. Typically, the electrical signal generated by a cell represents a pixel data sample from the cell.
Such imaging systems typically include an array controller that provides an interface between the imaging array and a processor that uses the imaging array to obtain samples of an image. Typically, the array controller generates the appropriate clock and control signals needed to obtain pixel data samples from the imaging array. In addition, the array controller usually processes the pixel data samples into a form suitable for use by a processor.
Some imaging arrays include a set of cells that generate black level pixels. One such type of imaging array is commonly referred to as a charge-coupled device (CCD). The black cells in a CCD array are usually cells that are coated with an opaque material. The black level pixels generated by such black cells usually enables a CCD array controller to establish black levels in the electrical signal generated by the CCD and to perform operations such as correlated double sampling.
A relatively wide variety CCD controllers are usually commercially available and at a relatively low cost. It may therefore be advantageous to incorporate CCD controllers into the design of imaging systems that use imaging arrays not having black cells. This would eliminate the costs of providing custom design array controllers to imaging arrays not having black cells. Unfortunately, prior CCD controllers usually do not function correctly if black pixels are not generated by the imaging array. Moreover, the inclusion of black cells in an imaging array wastes cells that could otherwise be available for sampling an image.
An imaging system is disclosed that uses an array controller which is adapted to imaging arrays having black cells to control an imaging array not having black cells. The imaging system enables the efficient use of imaging arrays by eliminating wasteful black cells and realizes a reduction in the cost of an imaging system by using commercially available array controllers such as CCD controllers.
In one embodiment, the imaging system includes an array controller that is adapted to process a scan line that includes one or more black pixels. The imaging system includes an imaging array not having black cells that generates a series of pixel data samples in response to light from an image. The imaging system includes circuitry for generating the scan line by synthesizing the black pixels and combining the black level pixels with the series of pixel data samples.
Other features and advantages of the present invention will be apparent from the detailed description that follows.